1. The Field of the Invention
The present invention relates generally to optical transmitters and receivers. More specifically, the present invention relates to optical transmitter and receivers that are capable of maintaining updated digital diagnostic parameters in persistent memory using microcode while avoiding interruptions to transceiver digital diagnostic communications and internal controls.
2. Background and Relevant Art
Computing and networking technology have transformed our world. As the amount of information communicated over networks has increased, high speed transmission has become ever more critical. Many high speed data transmission networks rely on optical transceivers and similar devices for facilitating transmission and reception of digital data embodied in the form of optical signals over optical fibers. Optical networks are thus found in a wide variety of high speed applications ranging from as modest as a small Local Area Network (LAN) to as grandiose as the backbone of the Internet.
Typically, data transmission in such networks is implemented by way of an optical transmitter (also referred to as an electro-optic transducer), such as a laser or Light Emitting Diode (LED). The electro-optic transducer emits light when current is passed through it, the intensity of the emitted light being a function of the current magnitude. Data reception is generally implemented by way of an optical receiver (also referred to as an optoelectronic transducer), an example of which is a photodiode. The optoelectronic transducer receives light and generates a current, the magnitude of the generated current being a function of the intensity of the received light.
Various other components are also employed by the optical transceiver to aid in the control of the optical transmit and receive components, as well as the processing of various data and other signals. For example, such optical transceivers typically include a driver (e.g., referred to as a “laser driver” when used to drive a laser) configured to control the operation of the optical transmitter in response to various control inputs. The optical transceiver also generally includes an amplifier (e.g., often referred to as a “post-amplifier”) configured to amplify the channel-attenuated received signal prior to further processing. A controller circuit (hereinafter referred to as the “controller”) controls the operation of the laser driver and post-amplifier.
Often, a host or other external device makes use of digital diagnostics in controlling the operation of the laser drive, post amplifier, or other components. For example, digital diagnostics may be used to monitor various parameters which may affect the operation of the transceiver. Often times the parameters are stored on persistent memory within the transceiver. A host would then access the parameters for further processing, which often included determining settings for the laser driver, post amplifier or other components to help ensure proper operation of the transceiver considering the conditions indicated by the parameters.
Previously, while the host updated the parameters on persistent memory, further access to the persistent memory was stalled during the update time. In particular, if updated parameters were available, the controller circuit would have to wait until the host was finished storing the parameters on the persistent memory. Other software logic or processes would also be stalled from accessing the persistent memory.